23 research outputs found

    Sedimentary imprint of Microcystis Aeruginosa (Cyanobacteria) blooms in grangent reservoir (Loire, FRANCE)

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    International audienceAnalysis of a sediment core taken from the Grangent reservoir in 2004 showed the presence of high concentrations of Microcystis aeruginosa KĂŒtz. colonies at the sediment surface (250 colonies · mL sediment−1) and also at depths of 25–35 cm (2300 colonies·mL sediment−1) and 70 cm (600 colonies · mL sediment−1). Measurements of radioactive isotopes (7Be, 137Cs, and 241Am) along with photographic analysis of the core were used to date the deep layers: the layer located at −30 cm dates from summer 2003, and that located at −70 cm from 1990 to 1991. The physiological and morphological conditions of those benthic colonies were compared with those of planktonic colonies using several techniques (environmental scanning electron microscopy [ESEM], TEM, DNA markers, cellular esterases, and toxins). The ESEM observations showed that, as these colonies age, peripheral cells disappear, with no cells remaining in the mucilage of the deepest colonies (70 cm), an indication of the survival thresholds of these organisms. In the benthic phase, the physiological conditions (enzyme activity, cell division, and intracellular toxins) and ultrastructure (particularly the gas vesicles) of the cells surviving in the heart of the colony are comparable to those of the planktonic form, with all the potential needed for growth. Maintaining cellular integrity requires a process that can provide sufficient energy and is expressed in the reduced, but still existing, enzymatic activity that we measured, which is equivalent to a quiescent state

    Enhancing data visualisation to capture the simulator sickness phenomenon: On the usefulness of radar charts

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    The data presented in this article are related to the research article entitled “The use of transdermal scopolamine to solve methodological issues raised by gender differences in susceptibility to simulator sickness” (Chaumillon et al., 2017) [1]. In an outstanding first demonstration, Kennedy et al. [2] showed that the Simulator Sickness Questionnaire (SSQ) is an appropriate tool to suit the purposes of characterizing motion sickness experienced in virtual environments. This questionnaire has since been used in many scientific studies. Recently, Balk et al. [3] suggested that the proposed segregation of SSQ scores into three subclasses of symptoms might limit the accuracy of simulator sickness assessment. These authors performed a factor analysis based on SSQ scores obtained from nine studies on driving simulators. Although their factor analysis resulted in the same three orthogonal classes of symptoms as Kennedy et al. [2], unlike this pioneering study, no items were attributed to more than one factor and five items were not attributed to any class of symptoms. As a result, they claimed that an exploration of each item score should give additional cues on individual profiles. To gain a better characterization of such item-by-item exploration, data utilised in this research are shown using a radar chart visualisation. Keywords: Simulator sickness, Radar charts, Drivin

    The role of body centre of mass on haptic subjective vertical.

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    International audienceWe examined to which extent proprioceptive information involved in the perception of subjective vertical corresponded to mechanical mass-based axes of the body. Blindfolded subjects (n=14) estimated their subjective vertical in conditions of deviation of the centre of mass (CM) of (1) the head-trunk unit or (2) the head segment alone. Verticality estimates (provided in a haptic modality) were significantly altered by the deviation of the head-trunk CM (by either 4 degrees or 7 degrees), indicating that the subjects used mass-based proprioceptive information stemming from the trunk. Modifying the perception of body orientation by shifting the trunk CM sideways while keeping the body vertical, deviates the subjective vertical towards the opposite side in a similar way to the so-called 'E-effect'. The induced deviations of head CM (9.33 degrees) did not affect the subjective vertical, suggesting that when the balance of the body is not threatened, proprioceptive or vestibular information is prioritized to estimate gravitational direction

    Driving simulator scenarios and measures to faithfully evaluate risky driving behavior: A comparative study of different driver age groups.

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    To investigate the links between mental workload, age and risky driving, a cross-sectional study was conducted on a driving simulator using several established and some novel measures of driving ability and scenarios of varying complexity. A sample of 115 drivers was divided into three age and experience groups: young inexperienced (18-21 years old), adult experienced (25-55 years old) and older adult (70-86 years old). Participants were tested on three different scenarios varying in mental workload from low to high. Additionally, to gain a better understanding of individuals' ability to capture and integrate relevant information in a highly complex visual environment, the participants' perceptual-cognitive capacity was evaluated using 3-dimensional multiple object tracking (3D-MOT). Results indicate moderate scenario complexity as the best suited to highlight well-documented differences in driving ability between age groups and to elicit naturalistic driving behavior. Furthermore, several of the novel driving measures were shown to provide useful, non-redundant information about driving behavior, complementing more established measures. Finally, 3D-MOT was demonstrated to be an effective predictor of elevated crash risk as well as decreased naturally-adopted mean driving speed, particularly among older adults. In sum, the present experiment demonstrates that in cases of either extreme high or low task demands, drivers can become overloaded or under aroused and thus task measures may lose sensitivity. Moreover, insights from the present study should inform methodological considerations for future driving simulator research. Importantly, future research should continue to investigate the predictive utility of perceptual-cognitive tests in the domain of driving risk assessment

    A multicentric, single arm, open-label, phase I/II study evaluating PSMA targeted radionuclide therapy in adult patients with metastatic clear cell renal cancer (PRadR)

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    Abstract Background Despite advancements in managing metastatic clear cell renal carcinoma (mccRCC) through antiangiogenic tyrosine kinase inhibitors and immunotherapy, there remains a demand for novel treatments for patients experiencing progression despite the use of these medications. There is currently no established standard treatment for patients receiving third therapy line. Prostate Specific Membrane Antigen (PSMA) whose high expression has been demonstrated in metastatic aggressive prostate adenocarcinoma is also highly expressed in neovessels of various solid tumors including renal cell carcinoma (RCC): 86% of clear cell RCC, 61% of chromophobe RCC, and 28% of papillary RCC. Therefore, PSMA may be a target expressed in metastatic ccRCC for radionuclide therapy using PSMA ligands radiolabeled with Lutetium-177 (PRLT). 177Lu-PSMA delivers ß-particle radiation to PSMA-expressing cells and the surrounding microenvironment with demonstrated efficacy in metastatic prostate cancer. Methods This is a multicenter phase I/II study designed to assess the tolerability and effectiveness of 177Lu-PSMA-1 in individuals with PSMA-positive metastatic clear cell renal cell carcinoma (ccRCC), identified through 68Ga-PSMA PET, conducted in France (PRadR). 48 patients will be treated with 4 cycles of 7.4 GBq of 177Lu-PSMA-1 every 6 weeks. The primary objective is to evaluate the safety of 177Lu-PSMA-1 (phase I) and the efficacy of 177Lu-PSMA-1 in mccRCC patients (phase II). Primary endpoints are incidence of Severe Toxicities (ST) occurring during the first cycle (i.e. 6 first weeks) and disease Control Rate after 24 weeks of treatment (DCR24w) as per RECIST V1.1. Secondary objective is to further document the clinical activity of 177Lu-PSMA-1 in mccRCC patients (duration of response (DoR), best overall response rate (BORR), progression fee survival (PFS) and overall survival (OS). Discussion Our prospective study may lead to new potential indications for the use of 177Lu-PSMA-1 in mccRCC patients and should confirm the efficacy and safety of this radionuclide therapy with limited adverse events. The use of 177Lu-PSMA-1may lead to increase disease control, objective response rate and the quality of life in mccRCC patients. Trial registration ClinicalTrials.gov: NCT06059014
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